Renewable dental slab



Sept. 24, 1929. 1. J. MccARTl-IYV RENEWABLE DENTAL SLAB Filed NOV. 23, 1927 3mm/ton Johw J. /V-(CARTHY Patented Sept. 24, 1929 UNITED STATES JOHN J. MCGARTHY, OF SAN FRANCISCO, CALIFORNIA RENEWABLE DENTAL SLAB Application filed November 23, 1927. Serial No. 235,349.

The present invention relates to improvements in dental slabs such as are used by the dentist in mixing his filling for a tooth. Itis customary at the present time to use for this purpose a slab usually made of glass, and it is necessary to clean this slab after each operation, which is a time-consuming process particularly in view of the fact that the mixture is sticky and hard to remove.

It is proposed in the present invention to provide a renewable slab or rather a renewable surface for the slab which allows a surface once used to be removed and discarded and a fresh surface to be exposed for use during the next operation. It is particularly proposed for this purpose to provide a continuous strip of suitable material having a smooth surface such as oilcloth, for instance,

and to guide the same over a supporting suri-O face softhat a section of the said strip lies 0n the top thereof, and to clamp this section to the supporting surface After this particular section has been used, the clamping means is released, the strip advanced, the used section torn off, and a new section is clamped on the supporting ace.

Further objects and advantages of my invent-ion will appear as the specification proceeds.

The preferred form of my invention is illustrated in the accompanying dra-wing, in which:

Figure 1 shows a longitudinal vertical section through my device taken along line 1-1 i of Figure 2;

Figure 2 a top plane view thereof; and

Figure 3 an end view of my device.

lVhile I have shown only the preferred y form of my invention, it should be understood that various changes or modifications may be made within the scope of the claims hereto attached without departing from the spirit of the invention.

In its preferred form, my device comprises a supporting plate 1 made substantially of the size of the dental slab new in use and adapted for fastening to a table or the like by means of a bracket 2 and a screw 3. rlhe supporting plate, which is preferably rectangular in form, has one end edge curled as shown at 4, while the other end edge is bevelled as shown at 6 to provide a cutting edge. 1t is formed with an all-around groove 7 in close proximity to the edges thereof, and has a threaded member 8 depending from its center.

A bracket 9 extends downwardly from one edge of the supporting plate. and has mounted therein a shaft 11 extending transversely of the plate at a distance therefrom and adapted te support a roll 12 of any suitable material, one end of which may be guided over the curled edge 4 of the supportingl plate and over the top thereof as indicated in Figure 1.

For clan'iping the exposed section of the surface material to the supporting plate, I provide a frame 13 formed to lit the groove Y and provided with depending guides 14 adapted to slide along opposite edges of the supporting plate, each two guides being interconnected by transverse members 15 extending below the supporting plate. The latter members are interconnected by a longitudinal bar 16-which may be hooked around the transverse members as shown at 17 and fastened thereto by means of screws 18.

The bar 16 is perforated as shown at 19 to receive the threaded member 8, and is formed with an offset member 21 which is also perforated as shown at 22 to receive the threaded member 8 so that the bar may be moved along the threaded member by means of a. nut 23 interposed between the bar and the offset member 21.

The frame 13 may be provided at spaced intervals with pins 24 adapted to penetrate the surface material and to extend into registering holes provided in the groove 7.

To use my device, the operator proceeds as follows: The surface material such as oilcloth is rolled over the curled edge 4 of the supporting` plate, and the frame 13 is placed on top thereof so as to register with tll'e groove 7. The bar 16 is then positioned with the nut 23 engaging the threaded member 8, and is fastened to the transverse members 15 by means of the screws 18. Thereupon. the nut 23 is threaded downwardly on the member 8, whereby the frame 13 is forced into the groove 7 and clamps the surface material into place so that the latter now forms a smooth working surface for the operator to mix his materials on.

After the dentist finishes one operation,

' he turns the nut 23 to rise en the member 8,

whereby the grip of the frame 13 on the material is released so that he may now advance the material until the used section projects beyond the cutting edge 6, whereupon he tear oil' the used section against the cutting edge, while a new section of surface material is pressed on top of the supporting plate 1. Serewing the nut 23 downward fastens the nent section to the supporting plate.

l. ln a renewable dental slab of the character described, a supporting` face, a surface element adapted to be placed thereon, and means for clamping all the edges of the sun face element upon the supporting face in a single movement.

2. In a renewable dental slab of the char acter described, a supporting face, a continnous surface element having means allowing successive sections to be placed on the supporting face, and means for clamping the entire border of a section to the supporting face in a single movement.

3. ln a renewable dental slab of the character described, a supporting face having a continuous groove surrounding the same, a frame overlying said groove, and means for urging the frame into the groove for clamping an interposed sheet of material upon the supporting face.

4. ln a renewable dental slab of the character described, a supporting face having a threaded member depending therefrom, a frame overlying said face having a substructure below the latter, and means engaging the threaded member and the substructure for urging the frame upon the supporting face for vclamping a sheet of material thereon.

5. Ina renewable dental slab of the character described, a supporting face grooved along edges thereof and having a threaded member depending therefrom, a frame overlying said grooves having a substructure below the supporting face, and means engaging the threaded member and the substructure for urging the frame into the grooves in clamping relation with an interposed sheet of material.

(i. ln a renewable dental slab of the character described, a supporting plate having a threaded member depending therefrom, a

frame overlying said plate having guide.

and means engaging the threaded member and the bar for urging the frame upon the supporting face for clamping an interposed sheet of material therebetween.

7. A renewable dental slab as deined in claim 6 in which the support-ing plate is grooved along the edges to receive the frame JOHN J. MGCARTHY. 

